I think the underlying issue is that when it comes to safety, privacy, and security, even if people aren't dying in a plane crash, you still need to do it with a basic level of competence. You cannot roll back a privacy leak.
Now if you're talking about features that don't touch these things, go nuts. And there lies a second issue: the identification and distinction between what stuff is "go nuts" and what stuff is "do it right the first time". You can't approach every project with the latter or you'll waste so much time in the design phase when really you should just throw your new CSS theme out there and see how it goes. But you just can't approach the "account creation" feature the same way.
